It has been over 100 years since the Wright brothers in U.S. invented an aircraft whose theory of aircraft lift was based on the wing structure of a curved top & flat bottom. With this wing structure, the resistance was decomposed to a downward “ballast force” in aircraft high velocity flight, so the safety and reliability in high velocity flight was ensured. The ballast force is proportional to the flight velocity and the aircraft could keep the smooth & effective controlling even in high velocity flight. The aircraft, however, may loop the loop and even flip over in the sky, in this way, the wing structure having a curved top & flat bottom produced no so called “lift force” but a downward “ballast force” with which the high velocity flight of aircraft was ensured in practice. And this point may be clear from the flight orbit of aircraft. In view of this, the invention put forwards a new lift theory absolutely different from the one of the Wright brothers'.